Non-fluorinated resorcinol and hydroquinone analogs as curing agents for fluoroelastomers

A fluoroelastomer masterbatch comprising a polyhydroxy-curable fluoropolymer and curing agent of Formula 1:

• wherein R1 and R5 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X;
• wherein R2, R3, and R4 are independently selected from the group consisting of OH, H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X,
• with the proviso that at least one of R2, R3, and R4 is OH;
• with the proviso that not more than 3 of R1, R2, R3, R4, and R5 are Cl or Br;
• wherein X is selected from the group consisting of Formula 2 and Formula 3:
• wherein R6, R7, R8, R9, and Rio are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, acetyl or methylsulfonyl which may be alkyl- or aryl-substituted or may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone;
• wherein R11, R12, R13, R14, R15, R16, R17, and R18 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone with the proviso that one of R11, R12, R13, R14, R15, R16, R17, and R18 is a single bond to —(Y)n—;
• wherein Y is selected from the group consisting of —SO2— and —O—;
• and
• wherein n is 0 or 1;
• with the proviso that at least one of R1, R2, R3, R4, and R5, is Cl, Br, a chlorine-containing C1-18 alkyl or alkoxy, a bromine-containing C1-18 alkyl or alkoxy, or X;
• with the proviso that, when X is present, at least one of R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, and R18 is Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, or sulfone;
• said curing agent being present at a concentration of about 1 wt % to about 50 wt %.

A curing agent and curing accelerator mixture comprising a curing agent of Formula 1:

• wherein R1 and R5 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X;
• wherein R2, R3, and R4 are independently selected from the group consisting of OH, H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X,
• with the proviso that at least one of R2, R3, and R4 is OH;
• with the proviso that not more than 3 of R1, R2, R3, R4, and R5 are Cl or Br;
• wherein X is selected from the group consisting of Formula 2 and Formula 3:
• wherein R6, R7, R8, R9, and Rio are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, acetyl or methylsulfonyl which may be alkyl- or aryl-substituted or may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone;
• wherein R11, R12, R13, R14, R15, R16, R17, and R18 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone with the proviso that one of R11, R12, R13, R14, R15, R16, R17, and R18 is a single bond to —(Y)n—;
• wherein Y is selected from the group consisting of —SO2— and —O—;
• and
• wherein n is 0 or 1;
• with the proviso that at least one of R1, R2, R3, R4, and R5, is Cl, Br, a chlorine-containing C1-18 alkyl or alkoxy, a bromine-containing C1-18 alkyl or alkoxy, or X;
• with the proviso that, when X is present, at least one of R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, and R18 is Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, or sulfone;
• and
• a curing accelerator selected from the group consisting of a quaternary phosphonium salt, a quaternary ammonium salt, and a tertiary sulfonium salt.

A salt for use as a fluoroelastomer curing agent and curing accelerator comprising a quaternary phosphonium salt or quaternary ammonium salt derived from a compound of Formula 1:

• wherein R1 and R5 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X;
• wherein R2, R3, and R4 are independently selected from the group consisting of OH, H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X,
• with the proviso that at least one of R2, R3, and R4 is OH;
• with the proviso that not more than 3 of R1, R2, R3, R4, and R5 are Cl or Br;
• wherein X is selected from the group consisting of Formula 2 and Formula 3:
• wherein R6, R7, R8, R9, and Rio are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, acetyl or methylsulfonyl which may be alkyl- or aryl-substituted or may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone;
• wherein R11, R12, R13, R14, R15, R16, R17, and R18 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone with the proviso that one of R11, R12, R13, R14, R15, R16, R17, and R18 is a single bond to —(Y)n—;
• wherein Y is selected from the group consisting of —SO2— and —O—;
• and
• wherein n is 0 or 1;
• with the proviso that at least one of R1, R2, R3, R4, and R5, is Cl, Br, a chlorine-containing C1-18 alkyl or alkoxy, a bromine-containing C1-18 alkyl or alkoxy, or X;
• with the proviso that, when X is present, at least one of R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, and R18 is Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, or sulfone.

A method of curing a polyhydroxy-curable fluoroelastomer, the method comprising:

• forming a curable fluoroelastomer composition comprising:
• the polyhydroxy-curable fluoroelastomer;
• a curing agent of Formula 1:
• wherein R1 and R5 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X;
• wherein R2, R3, and R4 are independently selected from the group consisting of OH, H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, and X,
• with the proviso that at least one of R2, R3, and R4 is OH;
• with the proviso that not more than 3 of R1, R2, R3, R4, and R5 are Cl or Br;
• wherein X is selected from the group consisting of Formula 2 and Formula 3:
• wherein R6, R7, R8, R9, and Rio are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, acetyl or methylsulfonyl which may be alkyl- or aryl-substituted or may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone;
• wherein R11, R12, R13, R14, R15, R16, R17, and R18 are independently selected from the group consisting of H, Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, and sulfone with the proviso that one of R11, R12, R13, R14, R15, R16, R17, and R18 is a single bond to —(Y)n—;
• wherein Y is selected from the group consisting of —SO2— and —O—;
• and
• wherein n is 0 or 1;
• with the proviso that at least one of R1, R2, R3, R4, and R5, is Cl, Br, a chlorine-containing C1-18 alkyl or alkoxy, a bromine-containing C1-18 alkyl or alkoxy, or X;
• with the proviso that, when X is present, at least one of R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, and R18 is Cl, Br, C1-18 alkyl which may contain chlorine or bromine substitutions, C1-18 alkoxy which may contain chlorine or bromine substitutions, nitro, nitrile, keto, aceto, or sulfone;
• and
• an acid acceptor;
• and
• heating the curable fluoroelastomer composition to cure the polyhydroxy-curable fluoroelastomer.

A compound of Formula 1A:

• wherein one of R1 and R2 is H and the other is OH;
• wherein one of R3 and R4 is H and the other is Formula 2A:
• wherein R5, R6, R7, R8, and R9 are independently selected from the group consisting of H, Cl, Br, OCH3, C(CH3)3, CH3, nitro, nitrile, keto, aceto, and sulfone;
• with the proviso that when R1 is OH and R3 is Formula 2A:
• exactly one of R5, R6, R7, R8, and R9 is selected from the group consisting of C(CH3)3, nitrile, aceto, and sulfone, and the remainder are H;
• exactly one of R5, R6, R8, and R9 is selected from the group consisting of nitro and keto, and the remainder of R5, R6, R7, R8, and R9 are H;
• exactly one of R5 and R9 is CH3 and the remainder of R5, R6, R7, R8, and R9 are H;
• exactly one of R6 and R8 is Br and the remainder of R5, R6, R7, R8, and R9 are H;
• or
• at least two of R5, R6, R7, R8, and R9 are independently selected from the group consisting of Cl, OCH3, C(CH3)3, nitro, nitrile, keto, aceto, and sulfone;
• with the proviso that when R1 is OH and R4 is Formula 2A:
• exactly one of R5, R6, R7, R8, and R9 is selected from the group consisting of C(CH3)3, nitrile, keto, aceto, and sulfone, and the remainder are H;
• exactly one of R5, R6, R8, and R9 is selected from the group consisting of Cl, Br, OCH3, and CH3, and the remainder of R5, R6, R7, R8, and R9 are H;
• exactly one of R5, R7, and R9 is nitro, and the remainder of R5, R6, R7, R8, and R9 are H;
• or
• at least two of R5, R6, R7, R8, and R9 are independently selected from the group consisting of Cl, Br, OCH3, C(CH3)3, CH3, keto, aceto, and sulfone;
• and
• with the proviso that when R2 is OH:
• exactly one of R5, R6, R7, R8, and R9 is selected from the group consisting of keto and sulfone, and the remainder are H;
• exactly one of R5, R6, R8, and R9 is selected from the group consisting of C(CH3)3 and aceto, and the remainder of R5, R6, R7, R8, and R9 are H;
• or
• at least two of R5, R6, R7, R8, and R9 are independently selected from the group consisting of Cl, C(CH3)3, nitrile, keto, aceto, and sulfone.